Keep in mind it was hand held both shots and if you look closely the branches look sharper in the F2.8 so the camera sharpened on a different spot. Yes this was auto focus too and hand held.

Plus it was breezy outside. i should have picked something different but I was in a rush to get to work.

As stated in my original response to this thread when putting so much time and effort into assessing resolution I would recommend the use or at least the inclusion of a calibrated resolution test chart which would allow quantitative rather than qualitative assessments to be made of the resolution and image quality for each camera lens/TC/aperture combination.